Xlib headers define many trivially named objects which can later cause
name collision problems when only cogl.h header is included in a program
or library. Xlib headers are now only included through including the
standalone header cogl-xlib.h.
https://bugzilla.gnome.org/show_bug.cgi?id=661174
Reviewed-by: Robert Bragg <robert@linux.intel.com>
Since we've had several developers from admirable projects say they
would like to use Cogl but would really prefer not to pull in
gobject,gmodule and glib as extra dependencies we are investigating if
we can get to the point where glib is only an optional dependency.
Actually we feel like we only make minimal use of glib anyway, so it may
well be quite straightforward to achieve this.
This adds a --disable-glib configure option that can be used to disable
features that depend on glib.
Actually --disable-glib doesn't strictly disable glib at this point
because it's more helpful if cogl continues to build as we make
incremental progress towards this.
The first use of glib that this patch tackles is the use of
g_return_val_if_fail and g_return_if_fail which have been replaced with
equivalent _COGL_RETURN_VAL_IF_FAIL and _COGL_RETURN_IF_FAIL macros.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
This factors out the CoglOnscreen code from cogl-framebuffer.c so we now
have cogl-onscreen.c, cogl-onscreen.h and cogl-onscreen-private.h.
Notably some of the functions pulled out are currently namespaced as
cogl_framebuffer but we know we are planning on renaming them to be in
the cogl_onscreen namespace; such as cogl_framebuffer_swap_buffers().
Reviewed-by: Neil Roberts <neil@linux.intel.com>
Instead of the stub winsys being a special case set of #ifdef'd code
used when COGL_HAS_FULL_WINSYS wasn't defined, the stub winsys now
implements a CoglWinsysVtable like all other winsys backends (it's just
that everything is a NOP). This way we can get rid of the
COGL_HAS_FULL_WINSYS define and also the stub winsys can be runtime
selected whereas before it was incompatible with all other winsys
backends.
Some of the virtual functions in CoglWinsysVtable only need to be
implemented for specific backends or when a specific feature is
advertised. This splits the vtable struct into two commented sections
marking which are optional and which are required. Wherever an
optional function is used there is now a g_return_if_fail to ensure
there is an implementation.
So that we can dynamically select what winsys backend to use at runtime
we need to have some indirection to how code accesses the winsys instead
of simply calling _cogl_winsys* functions that would collide if we
wanted to compile more than one backend into Cogl.
This migrates all the GLX window system code down from the Clutter
backend code into a Cogl winsys. Moving OpenGL window system binding
code down from Clutter into Cogl is the biggest blocker to having Cogl
become a standalone 3D graphics library, so this is an important step in
that direction.
This gives us a way to clearly track the internal Cogl API that Clutter
depends on. The aim is to split Cogl out from Clutter into a standalone
3D graphics API and eventually we want to get rid of any private
interfaces for Clutter so its useful to have a handle on that task.
Actually it's not as bad as I was expecting though.
